The present invention provides a nitrogenous composition resulting from the enzymatic hydrolysis of maize gluten.
The present invention also relates to a process for the preparation of such a nitrogenous composition and to the application thereof in culture media for the fermentation industries.
This nitrogenous composition may also be used as a feedingstuff or food additive in compositions for animals.
Maize gluten is known to be a source of nitrogen in the fermentation industries and a constituent of certain foodstuffs.
However, due to the viscoelastic properties of maize gluten, it must be solubilised if it is to be used as a source of nitrogen in bioengineering processes or as a feedingstuff or food additive.
This solubulisation of gluten may be carried out by chemical means (alkaline hydrolysis or acid hydrolysis) or by enzymatic means.
For example, patent application WO 95.28850 describes a method of solubilising plant proteins by using enzymes with phytase activity in combination with one or more enzymes with protease activity, one or more enzymes with lipase activity and one or more enzymes with glycosidase activity. These enzymes are extracted from microorganisms of the Bacillus, Pseudomonas, Kluveromyces, Saccharomyces, Aspergillus type.
The mixture thus hydrolysed is then used in animal feed.
The patent EP 518.999 describes the preparation of partially hydrolysed products by virtue of a specific treatment using a particular serine protease produced by Bacillus licheniformis. These products are of interest for the preparation of foods for human consumption and particularly in infant foods as an agent which limits the allergenic capacity of the proteins of full cream milk, and on account of their properties of better digestibility.
Patent application EP 461.261 describes the preparation of particular oligopeptides by enzymatic hydrolysis of plant proteins in order to obtain a high proportion of branched amino acids and the use thereof in food preparations intended for patients suffering from liver diseases.
A process which allows the preparation of an aromatiser by enzymatic hydrolysis of a substance rich in plant proteins without having to use purified exopeptidases to take away the bitterness, whilst giving it attractive organoleptic properties, has been described in patent EP 429.760.
The possibility of using an hydrolysate of plant proteins in a fermentation medium is also mentioned in patent application WO 94.25580.
However, none of these documents indicates or suggests that a hydrolysate of maize gluten having a particular composition in terms of its phosphorus and nitrogen content, its concentration of soluble and insoluble proteins and its distribution spectrum of amino acids, may be particularly suitable for fermentation applications, particularly in the field of fermentations of microorganisms which produce organic acids and/or in animal feed applications.